yeah, thats a good point. when I took the pipe off, (and cleaned it off a bit) I was able to blow through it. I also got my brother to put his finger over the end of the pipe -while I pedalled- and when he took his finger off, there was a steady hiss of air escaping....so, could the pipe be too plugged for the engine to run, but still allow some air through?. Id also like to be able to take the pipe off, but when i try to do so one of the nuts/bolts holding it on just rotates. Ill try and get that fixed (or, more likely, have it done).